also:
http://web.cecs.pdx.edu/~karavan/research/SMM_IISWC_preprint.pdf

------
good read about SMM/SMIs
http://phrack.org/issues/66/11.html
-------------

* for 81101                                                                     
  - read/apply Documentation/x86/usb-legacy-support.txt
    \ this doesn't seem to apply, but good read maybe
* 2.4.9.2.9 Locking SMM
 The following conditions can cause one or more cores to enter SMM without all cores entering SMM:
 • More than one IO device in the system is enabled to signal an SMI without hardware synchronization
 (e.g. using an end of SMI gate).
 • A single device may signal multiple SMI messages without hardware synchronization (e.g. using an end
 of SMI gate).
!• An SMI is received while one or more AP cores are in the INIT state. This may occur either during BIOS
 or secure boot.
 • A hardware error prevents a core from entering SMM.


=============
reported here:
https://bugzilla.kernel.org/show_bug.cgi?id=81101


bottom line:
https://bugzilla.kernel.org/show_bug.cgi?id=81101#c19
========

some relevant pdf files:
intel: http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-manual-325462.pdf

amd: http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2012/10/48751_BKDG_Fam_16h_Mod_00h-0Fh.pdf


